This value corresponds to a GUI element in the SSDM: the Migrate archive checkbox of the Specify Data for Migration screen. The SSDM writes this value to notesdtapp.ini from the user's GUI entry; Quest recommends you do not manually enter or change this value except at the direction of Quest Support.

... tells the program to not migrate the trash folder if the Specify Data for Migration screen does not appear, or sets the associated checkbox in that screen to be unmarked by default. The default setting (MigrateTrashFolder=1) tells the program to migrate the trash folder if the screen does not appear, or sets the associated checkbox to be marked by default. The most common use of this parameter is to provide the necessary entry value when the program is configured to hide the Specify Data screen. Chapter 4 of the Migrator for Notes to Exchange Scenarios Guide explains how this parameter relates to others used to customize the SSDM.